It says no such thing in the contract. It talks about the industry not Universal, so it would be highest standards for the industry as a whole, by default that is Disney who are seen as setting the gold standard (although the truth is arguable there). But even if we were to only look at Universal, what are these maintenance standards in Harry Potter that are so much superior to any other part of the park anyway? The language so vague as to be meaningless. You could have six people arguing for six different standards. Unless the rides are falling apart I don't think Disney's lawyers could do much of anything with it.
If 2nd gate is simply a designation rather than a proscription arbitration would likely not be required. If Disney had a burning desire to throw their lawyers at it (which they've shown no sign of so far) they could protest, but even then I strongly doubt they'd have much of a case and would probably lose. As written there's nothing to suggest that 2nd Gate is a limitation on the maximum number of gates just that at the time the agreement was written it was envisaged as a 2 gate park. This is the sort of minor change (company business unit was previously named Information Systems now it's called Technology Services for example) that happens all the time without arbitration or the involvement of lawyers at all.
The facts on record are:
- Disney hasn't even put any Marvel stuff in DCA yet despite having an area set aside for it and zero legal issues.
- Disney has a slew of expensive projects under construction or about to begin so any additional work would be 5+ years away from even starting and there's no obvious need for the Marvel IP at this time.
- Universal has publicly said they do not plan to relinquish the license
Anything else is wild speculation and wishful thinking. Could Disney at some point get the license back? Sure, I'd even say probably eventually, but it might be in 2 decades time. There's absolutely nothing pointing to it happening now.